2 research outputs found
Highly Enhanced Affinity of Multidentate versus Bidentate Zwitterionic Ligands for Long-Term Quantum Dot Bioimaging
High colloidal stability in aqueous conditions is a prerequisite
for fluorescent nanocrystals, otherwise known as “quantum dots”,
intended to be used in any long-term bioimaging experiment. This essential
property implies a strong affinity between the nanoparticles themselves
and the ligands they are coated with. To further improve the properties
of the bidentate monozwitterionic ligand previously developed in our
team, we synthesized a multidentate polyzwitterionic ligand, issued
from the copolymerization of a bidentate monomer and a monozwitterionic
one. The nanocrystals passivated by this polymeric ligand showed an
exceptional colloidal stability, regardless of the medium conditions
(pH, salinity, dilution, and biological environment), and we demonstrated
the affinity of the polymer exceeded by 3 orders of magnitude that
of the bidentate ligand (desorption rates assessed by a competition
experiment). The synthesis of the multidentate polyzwitterionic ligand
proved also to be easily tunable and allowed facile functionalization
of the corresponding quantum dots, which led to successful specific
biomolecules targeting
Sulfobetaine–Vinylimidazole Block Copolymers: A Robust Quantum Dot Surface Chemistry Expanding Bioimaging’s Horizons
Long-term inspection of biological phenomena requires probes of elevated intra- and extracellular stability and target biospecificity. The high fluorescence and photostability of quantum dot (QD) nanoparticles contributed to foster their promise as bioimaging tools that could overcome limitations associated with traditional fluorophores. However, QDs’ potential as a bioimaging platform relies upon a precise control over the surface chemistry modifications of these nano-objects. Here, a zwitterion–vinylimidazole block copolymer ligand was synthesized, which regroups all anchoring groups in one compact terminal block, while the rest of the chain is endowed with antifouling and bioconjugation moieties. By further application of an oriented bioconjugation approach with whole IgG antibodies, QD nanobioconjugates were obtained that display outstanding intra- and extracellular stability as well as biorecognition capacity. Imaging the internalization and intracellular dynamics of a transmembrane cell receptor, the CB1 brain cannabinoid receptor, both in HEK293 cells and in neurons, illustrates the breadth of potential applications of these nanoprobes